Safety device for cranking automobiles.



A. A. BNGSTROM. SAFETY DEVIGE FOR GRANKING AUTOMOBILES.

APPLICATION FILED-APR. 11, 1911. 1,040,296. Patented Oct. 8, 1912.

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A. A. ENGSTROM. SAFETY DEVICE FOR ORANKING AUTOMOBILES.

APPLICATION FILED APB..11, 1911.

Patented Oct. 8, 1912.

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aZrZkaraiZ BY A TTORNEY.

lV/TIVESSFS KW UNITED STATES PATENT OFFICE.

ARTHUR A. ENGSTROM, OF SPRINGFIELD, MASSACHUSETTS.

SAFETY DEVICE FOR CRANKING AUTOMOBILES.

To all whom it may concern:

Be it known that I, ARTHUR A. ENGS'IROM, a citizen of the United Statesof America,

residing at Springfield, in the county of Hampden and State oflllassachusetts, have invented new and useful Improvements in SafetyDevices for Cranking Automobiles, of which the following is aspecification.

This invention relates to improvements in starting devices for internalcombustion en- "gines and is particularly designed for starting suchengines as usedon automobiles.

' It sometimes happens, in manually cranking or starting the engine ofself-propelled vehicles, that the engine back fires or kicks back, asit-is termed, causing injury to the person operating'the startingdevice.

My invention is designed to overcome this serious objection.

In general, he invention consists in providing a device that will permitthe engine to be rotated in its proper or right-hand direction, but willautomatically release itself, should the engine suddenly reverse itsdirection of rotation.

In the drawings forming part of this app1ication,-Figure 1 shows anelevation view, partly in section, of my device. Fig. 2 is a transverse,sectional view on the line 2-2, Fig. 5, showing the locking pawls inoperative engagement. Fig. 3 is a similar view on the line 33-43, Fig.5, showing the pawls disengaged from the shaft. Fig. 4 'is 'a view onthe line H of Fig. 6 illustrating the spring ratchet device fortransmitting motion from the crank to the shaft. Fig. 5 is alongitudinal view on the line 5-5 of Fig. 2, and Fig. 6 is a similarview on the line 6-6 of Fig. 2. Referring to the drawings in detail, adesignates a crank provided with an operative handle I), the inner endof the crank being providedwith an enlarged head portion 0 which slipsover the outer end of a collar element on the shaft cl which element 'isprovided with ratchet teeth 6 that engage the locking pawl f that isnormally pressed Specification of Letters Patent.

Application filed April 11, 1911. Serial No. 620,451.

Patented Oct. 8, 1912.

forward by means of the compression spring 9. This pawl and ratchetdevice serves to transmit motion from the crank to the collar element onthe shaft when rotated in one direction, and slip idly in the oppositedirection.

The inner end of the shaft (Z is provided with a clutch device b that isadapted to engage a similar clutch device 11 on the engine shaftNormally the shaft (Z is forced outward by means of the spring It: so asto disengage the clutches h and i. In order to lock the clutches k and itogether, the operator pushes inward on the crank a against the tensionof the spring is during the starting operations.

Referring now to the detailed construction of the safety device, mdesignates a casing that is adapted to be secured to the fixed part ofthe framework. as 0, by means of a bolt p. This casing has mountedwithin an extended portion thereof a pawl which is pivoted at the pointr and is forced inward by means of the spring .9 toward the teeth t of acam-ring a. the inner surface of which is provided with cam shoulders 41and w and projections to, to prevent the pawls y from moving too far orbeing wedged in the ring a. The cam shoulders serve the purpose ofmanning the locking pawls into and out ofengagement with the teeth 3 onthe shaft (I. Fig. 3 shows these pawls disengaged from the teeth I andFig. 2 shows them in engagement.

7 The locking pawls y are pivotally mounted in an annular collar member4. as shown at 5, which collar portion is located within the cam-ring uand it should be noticed that the collar portion is integral with thepartin which the ratchet teeth e are cut, and that the shaft (Z in whichthe teeth 3 are cut extends through the collar portion to provide abearing forthe end of the shaft 03 and has endwise movement therein whenthe 7 designates a screw for loosely and rotatably securing thepart a tothe shaft ol. 8 designates arecess in the-collar EOItlOIl, and 9 ashoulder on the shaft d whic moves in the recess 8. This spacerepresents the travel the handle amoves through when the spring Z: iscompressed to effect the locking engagement of the clutch members It andi.

The locking pawls 51 are provided with cam shoulders '10, andpower-transmitting shoulders ll. are formed on two of these pawls whichengage the oppositely located projections The locking ends of thesepawls which engage the teeth 3 of the shaft (Z are shown at 12, whenpower is trans mitted from the crank a to the shaft (Z through thecollar 4 and pawls y. The locking pawls y are normally pressed inwardtoward the shaft (Z by means of the springs 13.

Referring now to the operation of'the device, considerlng the awls .y asbein in locking engagement with the teeth 3 of the shaft (Z, as shown inFig. 2: Power istra'nsmitted by the operator from the crank a to thecollar portion 4 by means of the teeth 0, which collar portion carriesthe pawls y. The shoulders 11 of two of these pawlsare in engagementwith the oppositely disposed projections :22 of the cam ring a whichretates this ring and, by reason of the part 12 of the pawls engagingthe teeth 3, the shaft ('7 will be rotated in the direction shown by thearrow 14, at the same time i the pawl 1 1 that engagesthe teeth t of therum ring 1/. slips idly thereover. Should a back-fire occur in theengine, which of course turns the shaft din the opposite direction, thering a will be-immediately locked by means of the pawl q, and the pawlsy will be cammed out oflocking engagement with the teeth 3 by means ofthe cam-shoulders on the ring u (as shown in Fig. 3) permitting theshaft d to turn idly within its bearings and without injury to theoperator. V In order to reengage the pawls y with the teeth 3, the operaor again rotates the crank. a forward and, as before, brings the pawlsback into the position shown in Fig. 2.

It will be not-iced that the rear ends of the pawls engage one set ofcams when in locked )osition with the shaftd, and their forwar endsanother set when in unlocked position.

15 designates a closing rm that 15 located between the head 0 of t 1ecrank and the casing in, with WlllCll it is held in place 'by thescrew-threads 16. This ring is screwed against the cam-ring u withsulficient pressure to prevent this ring turning .forward when theoperator rotates the crank forward to disengage the pawls y from theinoperative position, as shown in Fig. 3, and

. allow them to snap down into the teeth 3,

tates with the pawls.- The ring 15 is held in fixed-position by'means ofa screw 17. From this construction, it will be seen that when the engineback fires that the only movement that can be transmitted to the crankwould be that represented b5 the space 18. v L

It will be seenthat some of the locking pawls 3 are not provided withtransmitting shoulders 11, but that all of the pawls are provided withportions '12 which'engage the teeth 3 during the cranking operations.

From the description it will be seen that I have produced a very simpleand'eificient safety device for starting internal combustionengineswithout injury to the operator. What I claim, is I 1. In a crankingdevice forinternal combustion engines, the combination with a movablecamring, the-inner surface of which is provided with stop projectionsand cammin surfaces a series of awls havin shoulders to engage the stopprojections, a collar member in which; the pawl's are mounted, acranking device proper, a looking engagement between the collar memberand the crankingdevice, a shaft provided with teeth with which the pawlsare a-dapt ed to engage,fimeans for locking the camrmg agalnst reversemovement but permitting it to rotate forward in unison with the:

crank and shaft, whereby when the ,-'crank is moved forward the pawlswill bc ,thrown into locking engagement with the shaft and will bedisengaged therefrom *upon'the reverse movement of the'shaft,

2. In a safety cranking device, a cam-h ring, the inner surface of whichis -provided withcam shoulders and driving projection? a collar havinglocking pawls 'mounte therein, some of the pawls having drivingshoulders to engage the projections on-the' cam-ring, and all of thepavtils being forced into engagement. with thedrive-shaft dur ing thecranking operation by the cam shoulders, said drive-shaft having. teethto, receive the inwardly projecting ends of-the pawis, means to hold thering against reverse movements should the engine backfire, and means fortransmittingmotion to the collar on which the pawls are mounted.

3. A safety cranking device comprising a cam ring member havingcam-shoulders on its inner surface, a shaft provided with teeth, lockingpawls ada ted to enga e the teeth thereof and opera le from sai camshoulders, a recessed collar member for supportin the pawls-to move sameinto and out of engagement with the teeth of the shaft, and a awl andratchet device to operate the collar member, said shaft bein adapted tomove axially in said collar and said recess.

4. A safety cranking device comprising their inoperative position, andmeans to prea shaft member, a collar member, means to .vent said ringfrom rotating in a reverse 10 operlatedthe '(izollatr member-1', facaIln-ring, direction. paw s a apte to e o erate romt ecamring and toengage t e shaft member for ARTHUR ENGSTROM' rotating the same, means tofrictionally Witnesses: clamp the cam-ring against forward move- K. I.CLEMONS, ment when the pawls are disengaged from HARRY W. BOWEN.

Caries of this patent may be obtained for five cents each, by addressingthe "Commissioner of Patents,

Washington, I). C.

